This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Several epidemiology reports have suggested that by-products of drinking water purification results in late term abortion in human populations. EPA has now instituted a program which requires all Public Utility Districts to notify all water users of the trihalomethane concentration at the central source. Additional studies are required to determine levels at the tap, risks associated with those levels and the mechanism(s) of toxic action. The nonhuman primate provides the only appropriate animal model for this kind of study.